Subramanian, KaushikSubramanian, KaushikAndrus, LiamAndrus, LiamPawlowski, MichalWang, YeTkaczyk, TomaszBen-Yakar, AdelaBen-Yakar, AdelaBen-Yakar, Adela2021-07-302021-07-302021Subramanian, Kaushik, Subramanian, Kaushik, Andrus, Liam, et al.. "Ultrafast laser surgery probe with a calcium fluoride miniaturized objective for bone ablation." <i>Biomedical Optics Express,</i> 12, no. 8 (2021) Optical Society of Americ: 4779-4794. https://doi.org/10.1364/BOE.426149.https://hdl.handle.net/1911/111043We present a miniaturized ultrafast laser surgery probe with improved miniaturized optics to deliver higher peak powers and enable higher surgical speeds than previously possible. A custom-built miniaturized CaF2 objective showed no evidence of the strong multiphoton absorption observed in our previous ZnS-based probe, enabling higher laser power delivery to the tissue surface for ablation. A Kagome fiber delivered ultrashort pulses from a high repetition rate fiber laser to the objective, producing a focal beam radius of 1.96 μm and covering a 90×90 μm2 scan area. The probe delivered the maximum available fiber laser power, providing fluences >6 J/cm2 at the tissue surface at 53% transmission efficiency. We characterized the probe’s performance through a parametric ablation study on bovine cortical bone and defined optimal operating parameters for surgery using an experimental- and simulation-based approach. The entire opto-mechanical system, enclosed within a 5-mm diameter housing with a 2.6-mm diameter probe tip, achieved material removal rates >0.1 mm3/min, however removal rates were ultimately limited by the available laser power. Towards a next generation surgery probe, we simulated maximum material removal rates when using a higher power fiber laser and found that removal rates >2 mm3/min could be attained through appropriate selection of laser surgery parameters. With future development, the device presented here can serve as a precise surgical tool with clinically viable speeds for delicate applications such as spinal decompression surgeries.engPublished under the terms of the OSA Open Access Publishing AgreementUltrafast laser surgery probe with a calcium fluoride miniaturized objective for bone ablationJournal articleboe-12-8-4779https://doi.org/10.1364/BOE.426149